It’s really annoying(to me). Can you turn off the transparent faces in edit mode? In 2.41 I was able to keep my faces solid while modeling.
Also all my models from 2.41 show up without the transparent faces in 2.42, just like I want them. But I can find an option for this in 2.42. It seems to be forced into the theme settings.
Try this button. It’s state gets saved with your project most likely. (“Limit selection to visible” - 4th from the left next to “face select mode” button).